Microbial Remediation of Pesticide Polluted Soils

The increasingly rapid growth of both, population- and food demands has driven a research race in food production efficiency through the last century, which has made the pesticide use seemingly unavoidable. However, many pesticides are very persistent and tend to accumulate in the ecosystem, often threatening biodiversity and public health. Although abiotic degradation of these compounds plays a role in many cases, the biodegradation of pesticides by microorganisms is usually the most important and dominant process. This natural degradation varies from site to site, depending on several factors, but it can be favourably improved by applying techniques such as bioaugmentation and biostimulation, which can lead to the cleaning-up of pesticide-contaminated soils. The present chapter introduces the most recent findings in the field of bioremediation of pesticides, critically discussing the main bottlenecks and how to overcome them. Factors affecting biodegradation of pesticide-polluted soils are presented, with a clear focus on the enrichment and selection strategies for relevant microbial strains. Case studies on bioaugmentation of contaminated soils and future trends are also described, including the microbial degradation of pesticide mixtures through mixed culture technology.